Slide-induced impulse waves in mountainous regions

Helge Fuchs and Robert M. Boes

Impulse waves occur as a natural hazard particularly in mountainous regions with lakes surrounded by a steep shoreline. Landslides, rockslides, glacier calvings or avalanches then transfer its momentum to the water body thereby generating large tsunamigenic waves. At lakes, damages are expected for the shore vegetation or possible infrastructure. In presence of a reservoir, potential dam overtopping could lead to downstream damages due to (a) direct wave impact, (b) float impact, (c) deposited float and debris or even (d) complete dam failure. Using physical model tests conducted within various PhD theses at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of ETH Zurich, the impulse wave generation and the wave-shore interaction were intensively investigated. Based on a computation guideline published in 2009, the possible hazard potential may be assessed. The present contribution provides an overview on impulse waves and an evaluation of underwater slide propagation and deposition features. These data are useful for the calibration of numerical models or the above mentioned assessment approach.

2016/1 265-273